The present invention relates generally to hacksaws utilizing an elongated blade maintained in tension between respective legs of the saw frame. More particularly, the invention relates to such a hacksaw that incorporates an improved blade tensioning mechanism.
A conventional hacksaw blade defines respective mounting holes at each end for receipt on blade pins carried by the hacksaw. One of these pins will be often be fixed with respect to the saw frame. The other pin will be movable in some manner to facilitate installation of the blade.
For example, in one commonly-used arrangement, the movable blade pin may be mounted to a threaded member extending through a hole defined in the saw frame. A wing nut or the like engages the threaded member to effect movement of the movable blade pin toward or away from the fixed blade pin. In this manner, the distance between the respective blade pins may be shortened to facilitate installation of the blade. After the blade has been installed, the wing nut is tightened to lengthen the distance between the blade pins and place the blade in tension.
It will be appreciated that changing blades with such a mechanism can be a relatively time consuming procedure. In addition, it is often difficult to maintain a relatively constant tension in each new blade. As such, the prior art has provided more complex mechanisms that are intended to expedite blade change, provide better tension control, or both. Examples of such mechanisms are shown in U.S. Pat. No. 4,571,829 to Withers, Jr. and U.S. Pat. No. 4,466,471 to Thomson.